Tyr-301 phosphorylation inhibits pyruvate dehydrogenase by blocking substrate binding and promotes the Warburg effect

J Biol Chem. 2014 Sep 19;289(38):26533-41. doi: 10.1074/jbc.M114.593970. Epub 2014 Aug 7.

Abstract

The mitochondrial pyruvate dehydrogenase complex (PDC) plays a crucial role in regulation of glucose homoeostasis in mammalian cells. PDC flux depends on catalytic activity of the most important enzyme component pyruvate dehydrogenase (PDH). PDH kinase inactivates PDC by phosphorylating PDH at specific serine residues, including Ser-293, whereas dephosphorylation of PDH by PDH phosphatase restores PDC activity. The current understanding suggests that Ser-293 phosphorylation of PDH impedes active site accessibility to its substrate pyruvate. Here, we report that phosphorylation of a tyrosine residue Tyr-301 also inhibits PDH α 1 (PDHA1) by blocking pyruvate binding through a novel mechanism in addition to Ser-293 phosphorylation. In addition, we found that multiple oncogenic tyrosine kinases directly phosphorylate PDHA1 at Tyr-301, and Tyr-301 phosphorylation of PDHA1 is common in EGF-stimulated cells as well as diverse human cancer cells and primary leukemia cells from human patients. Moreover, expression of a phosphorylation-deficient PDHA1 Y301F mutant in cancer cells resulted in increased oxidative phosphorylation, decreased cell proliferation under hypoxia, and reduced tumor growth in mice. Together, our findings suggest that phosphorylation at distinct serine and tyrosine residues inhibits PDHA1 through distinct mechanisms to impact active site accessibility, which act in concert to regulate PDC activity and promote the Warburg effect.

Keywords: Cell Proliferation; Phosphotyrosine Signaling; Pyruvate Dehydrogenase Complex (PDC); Tumor Metabolism; Warburg Effect.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • 3T3 Cells
  • Amino Acid Substitution
  • Animals
  • Carbohydrate Metabolism
  • Catalytic Domain
  • Cell Hypoxia
  • Cell Line, Tumor
  • Cell Proliferation
  • Epidermal Growth Factor / physiology
  • Humans
  • Mice
  • Mice, Nude
  • Neoplasm Transplantation
  • Oxidative Phosphorylation
  • Phosphorylation
  • Protein Binding
  • Protein Processing, Post-Translational*
  • Pyruvate Dehydrogenase (Lipoamide) / chemistry
  • Pyruvate Dehydrogenase (Lipoamide) / genetics
  • Pyruvate Dehydrogenase (Lipoamide) / metabolism*
  • Pyruvic Acid / chemistry
  • Receptor, Fibroblast Growth Factor, Type 1 / metabolism
  • Tumor Burden
  • Tyrosine / metabolism

Substances

  • Tyrosine
  • Epidermal Growth Factor
  • Pyruvic Acid
  • Pyruvate Dehydrogenase (Lipoamide)
  • pyruvate dehydrogenase E1alpha subunit
  • FGFR1 protein, human
  • Receptor, Fibroblast Growth Factor, Type 1

Associated data

  • PDB/1NI4